Hi. I'm pretty sure this is a strange question- I'm looking for a way to digitally filter out most frequencies from the audio output of my windows XP computer. In other words, I want to pass only the frequencies close to some given center frequency, to my speakers. Any advice?

Such filtering is called band pass. Band passes parameters can be applied to a variety of filter types. This should be easy in most audio editors.

If you could play from Foobar2000 and use the crossover component, if a standard (low order, butterworth, bessel, or chebyshev) does the trick. (I use this for 4 way active speakers.) Or use the convolver for any more exotic filter you want. If you need to play from another application then I'm not so sure what the best method would be.

Ken

Okay, easy to do in foobar, but that is limited to playing back audio files. Specifically I want to apply the filter to the signal recieved by the mic-in on my computer. So I guess I am looking either for a new application completely to do what I mentioned in my first post, or some way to moniter the mic-in in foobar, live.